Let EB and CF be two heights. Then quadrilateral EBCF is rectangle, so BC=EF=5 m. It is given that bases are BC=5 m and AD=11 m. Triangles ABE and DCF are congruent, thus,

Consider right triangle ABE, by the Pythagorean theorem

Answer: 
Answer:
D
Step-by-step explanation:
Since it’s asking for numbers between -1 and 8 the equation cannot contain a equal symbol therefore it must be D
Answer:
Step-by-step explanation:
(r/s)(x) is the quotien of r(x) = 3x - 1 and s(x) = 2x + 1:
r 3x - 1
(-----)(x) = ----------
s 2x + 1
Answer:
c=80
Step-by-step explanation:
Based on my reading the critical damping occurs when the discriminant of the quadratic characteristic equation is 0.
So let's see that characteristic equation:
20r^2+cr+80=0
The discriminant can be found by calculating b^2-4aC of ar^2+br+C=0.
a=20
b=c
C=80
c^2-4(20)(80)
We want this to be 0.
c^2-4(20)(80)=0
Simplify:
c^2-6400=0
Add 6400 on both sides:
c^2=6400
Take square root of both sides:
c=80 or c=-80
Based on further reading damping equations in form
ay′′+by′+Cy=0
should have positive coefficients with b also having the possibility of being zero.
Put the values of x to the equations of the functions:
1. f(9) → x = 9; f(x) = -3x + 10
f(9) = -3(9) + 10 = -27 + 10 = -17
2. f(-2) → x = -2; f(x) = 4x - 1
f(-2) = 4(-2) - 1 = -8 - 1 = -9
3. f(-5) → x = -5; f(x) = -2x + 8
f(-5) = -2(-5) + 8 = 10 + 8 = 18